Intraocular lens

ABSTRACT

An intraocular lens utilizing an optical lens portion adapted to position over the pupil along the optical axis. A first member and an adjustable second member, space apart under the cornea extend away from the lens portion to the periphery of the iris. The adjustment of the second member permits wedging of the intraocular lens beneath the optical portion of the cornea.

BACKGROUND OF THE INVENTION

The present invention relates to intraocular lens systems orpseudophakos generally implanted after removal of the natural lens of aneye as a result of a cataract condition.

The problem of correcting impaired vision of an eye after cataractsurgery has been tackled in various ways. The prior methods forremedying the blurred vision condition has included the use ofeyeglasses which has the undesirable side effect of reducing peripheralvision and magnifying the visual image obtained by the eye beingcorrected. Cataract removal and correction of vision by eyeglassesproduces double vision. Contact lenses offer a better solution, althoughnot a perfect one, since magnification still occurs. Moreover, contactlenses are relatively difficult to wear by the majority of cataractpost-operative patients.

Intraocular lens implantation solves the majority of the opticalproblems associated with natural lens removal. New problems arise withthe insertion of pseudophakos, for example, the fixation, support,relocation, and sterilization of such artificial lens systems.

Most of the prior intraocular lenses have been positioned in theanterior chamber of the eye. The Ridley, Epstein, Binkhorst, andCopeland, lenses employ a variety of clips, loops, and stabilizers tofasten the lens to the iris portion of the eye. Reference is made toU.S. Pat. No. 3,906,551 issued to Otter and U.S. Pat. No. 3,922,728 toKrasnov as representative of artificial lens designs. Insertion of theselenses requires great surgical skill.

Other lenses have been placed in the posterior chamber of the eye, withless success because of the difficulty involved with such fixation andpositioning. Ophthalmologic surgeons have favored anterior chamberintraocular lens placement because of the relative remoteness of theposterior chamber and of the additional skill needed to successfullyperform posterior chamber implantations. In this regard, the U.S. Pat.No. 3,711,870 to Deitrick, and the U.S. Pat. No. 3,991,426 to Flomdescribe examples of posterior chamber lens devices.

An early development by Strampelli, in 1953, used the idea of placing anintraocular lens over the iris and into a wedging configuration betweenthe periphery of the iris and the connecting sclera commonly referred toas the anterior chamber angle. This lens made extensive contact with thetrabeculum and corneal endothelium, causing damage to both structures.

A later variation of the Strampelli lens was the Choyce family of lenseswhich reduced the radius thickness of the Strampelli lens. Less tissuereactive materials were used for the entire lens, also. However, theChoyce lenses have a tendency to dislocate inferiorly, which requiresreentry into the eye for relocation of the lens or insertion of a newlens. To avoid a misfitting of the lens, the proper sized lens must beinitially inserted. Measurement across the iris, from opposite points ofthe angle, vary from about 12 to 14 millimeters. Exact dimensioningacross the anterior chamber of an eye cannot be determined accuratelywithout entering the eye. Incision of the eye invariably releasesaqueous humor causing the eye to change its exterior shape; becomingmore oblate. Such deformation renders actual measurement unlikely, ifnot impossible. The method now used to measure the Choyce lens adds afixed dimension to the horizontal exterior white-to-white length. Theresults are not completely accurate.

If an accurate measurement is to be obtained, the eye surgeon must havethe proper sized lens immediately prepared for implantation. Thisprocedure entails maintaining a complete line of intraocular lensesaccording to length and refractive power.

The current procedure for insertion of the Choyce lens requires fillingthe eye anterior chamber with balanced salt solution after insertion ofa lens and later nudging or tapping the sclera perpendicular to the axisof the lens. If the lens is stable, the fit is proper, if the lens movesit is too short. The latter instance requires re-opening the chamber andinserting a longer lens. Post-operative patients are examined and madeto blink to see if the lens is stable, again if the lens moves a newlonger lens is required for re-insertion.

SUMMARY OF THE INVENTION

In accordance with the present invention a novel adjustable intraocularlens is provided. An optical zone or lens portion adopted forpositioning over the pupil includes a first member, fixed to the lensportion, which extends away from the same to the periphery of the iris.A second adjustable member also connects to the lens portion.Adjustments of the extension of the second member away from the lensportion, wedges the intraocular lens into place beneath the cornea of aneye. The wedging takes place at an angle or scleral spur at theperiphery of the iris in the anterior chamber.

The first member may include two edge portions spaced from one anotherabout the outer periphery of the iris. This provision would provide aroughly tripod support for the optical zone. Likewise, the second membermay include two spaced edge portions which permits the insurance of atleast a tripod support if one of the edge portions of the first andsecond members does not wedge properly.

The second adjustable member has several possible configurations, theimportance being that the second adjustable member expands or contractsto effect the wedging of the intraocular lens. The second adjustablemember may include a first tongue or projection connected to the lensportion and a second tongue or projection being adjacent the firsttongue. Means for positioning the first tongue in relation to the secondtongue effectively wedges the intraocular lens into a fixed position bydint of the contact of the edges of the first and second member at theangle or scleral spur portion of the eye.

The positioning means of the second member may take many forms and mayinclude, as an element of one of these forms, clamping means forreleasably holding the first tongue against the second tongue. The firstand second tongues may have serrations on opposing surfaces that mateand lock the respective position of the tongues at a plurality ofpositions. Thus, the extension of the second member may be predeterminedby "clicking" the first and second tongues into place with respect toone another. The clamping means would hold and guide the mated serratedsurfaces in position with respect to one another, yet allow the seekingof a new position by permitting the separation of the tongues duringrelative movement therebetween. The serrations may be designed to allowback-and-forth or one-way movement of the second tongue or the relativemovement between the tongues.

In addition, the present invention may include a pair of ears on each ofthe tongues for receiving a positioning force applied thereto. Forinstance, the ears may shorten or lengthen the second adjustable memberby inserting elongated surgical tools through the limbus or cornea. Thisfeature would permit readjustment of the fit of the intraocular lens forvarious reasons; for example, reappearance of aqueous humorpost-operative to cataract removal, changing of the shape of the eye.

The avoidance of intraocular surgical manipulations would be realizedwith means for continually forcing the second tongue away from the firsttongue. Such means may take the form of an elastic member contacting apair of studs on extensions each radiating from the first and secondtongues. The force of the elastic member urges separation of the tonguesand thus maintains the wedging action of the intraocular lens.

As may be surmized, a new and useful intraocular lens has been providedfor correcting the vision of eyes, especially after cataract removal.

It is, therefore, an object of the present invention to provide anintraocular lens useable after extracapsular or intracapsular cataractremoval.

It is another object of the present invention to provide an intraocularlens easily insertable and having an adjustable fit to accommodatevariations in eye sizes and shapes.

It is yet another object of the present invention to provide anintraocular lens having adjustability characteristics before and afterinsertion within an eye.

It is another object of the present invention to provide an intraocularlens which obviates the need for loop, clips, and other appendagesthereto, yet fixes within the eye quickly and safely withoutpremeasurement of the external or internal dimensions of the eye.

It is yet another object of the present invention to eliminate orgreatly reduce the inventory of various sized intraocular lenses for useduring cataract surgery.

It is another object of the present invention to provide an intraocularlens whose fit is automatically adjusted within the eye.

The invention possesses other objects and advantages especially asconcerns particular features and characteristics thereof which willbecome apparent as the specification continues.

Various aspects of the present invention will evolve from the followingdetailed description of the preferred embodiments thereof which shouldbe taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of the intraocular lens within an eye.

FIG. 2 is a top plan view of the invention.

FIG. 3 is a view taken along line 3--3 of FIG. 2

FIG. 4 is a view taken along line 4--4 of FIG. 2.

FIG. 5 is a sectional view showing the relative movement of the tonguesof FIG. 4.

FIG. 6 is a sectional view of a portion of the invention showing avariation of the design of the interlocking surfaces of the tongues.

FIG. 7 is a sectional view of a portion of the invention showing theprovision of ears.

FIG. 8 is a sectional view of a portion of the invention showingcontinual forcing means.

FIG. 9 is a partially broken plan view of the invention showing twospaced edge portions of the second adjustable member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention as a whole depicted in the Figures is denoted by referencecharacter 10 and includes, as one of its elements, a lens portion 12lying over the pupil 14 of an eye 16. The lens portion 12 may beconstructed of any biologically inert, transparent material, such asmethylmethacrylate quartz, ophthalmic glass, and other polymerizedmaterials known in the art.

Fixed to lens portion 12 is a first member 18 and a second adjustablemember 20 which may be formed of the same material as lens portion 12 orof different material from lens portion 12. Of course, first and secondadjustable members 18 and 20 must be biologically inert andnon-absorbtive in relation to living tissue. The first and secondmembers 18 and 20 extend from lens portion 12 to the periphery of iris22 of eye 16. The intraocular lens 10 is placed beneath the cornea 24 ofeye 16 by known surgical methods and wedges into a fixed position withineye 16 at the vicinity of angle 26 (the general meeting place of cornea24, iris 22, and sclera 28), FIG. 1. The intraocular lens 10 may wedgeinto the angle 26 at the scleral spur (not shown). Lens portion 12 maytake the form of a plano-convex optical configuration, but may be of anylens shape and power known in the art of vision correction. Typically,lens portion 12 may possess between 17 and 21 diopters of power.

FIG. 2 most clearly shows an embodiment of the intraocular lens 10 wherefirst member 18 includes edge portions 30 and 32 spaced from each otheralong angle 26. The lens portion 12 first and second member 18 and 20transition necessitates sloped portion 34. Second adjustable member 20may embrace a single edge portion 36, FIG. 2, or two spaced edgeportions 38 and 40 FIG. 9. The lens 10 embodiment shown in FIG. 2 offerstripod support, while the embodiment of lens 10 depicted in FIG. 9provides quadrapod support, and at least tripod support if one edgeportion of either first or second member 18, 20 does not contact thevicinity of angle 26.

The second adjustable member 20 may embrace a number of embodiments eachdesigned to fill a particular medical need. For instance, FIGS. 1-5 showa first tongue 42 connected to lens portion 12 via sloped portion 34. Asecond tongue 44 lies adjacent the first tongue 42 in a slidablerelationship. Means for positioning the tongues 42 and 44 in relation toone another also contributes to the adjustability of the second member20. Clamping means 45 comprising clamps 46, 48, 50, and 52 releasablyholds tongues 42 and 44 against one another, FIGS. 1-8. The clamps 48and 52 of FIG. 3 illustrates an embodiment of the clamps. Clamp 48, asexemplar of the remaining clamps 46, 50, and 52, has a first arm 54 andan arm 56; arms 54 and 56 are angularly oriented with respect to oneanother and integrally formed. Arm 54 of clamp 48 fixes to second tongue44 by gluing, sonic welding, or molding and the like. Second arm 56presses tightly upon the surface 58 of first tongue 42, thus pressingtongue 42 into frictional engagement of tongue 44. The second arm 54 ofclamp 48 must be able to releasably hold the first tongue 42 to secondtongue 44 to permit a degree of sliding therebetween. The net result ofthe sliding between tongues 42 and 44 is the extension or retraction ofsecond adjustable member 20 from, or to, lens portion 12. Clamps 46, 48,50, and 52 also guide the movement of tongues 42 and 44.

Serrations 66 and 68 may be added to surfaces 60 and 62 of tongues 42and 44, to provide a plurality of positions or stops therebetween.Clamps 50 and 52 bear on surface 64 of tongue 44 to aid in mating thetongues to the stops provided by serrations 66 and 68. Clamps 46, 48,50, and 52 are constructed of resilient material such as nylon,methylmethacrylate and like biologically neutral compounds. Withreference to FIG. 5, a positioning force denoted by arrow 70 will forcethe clamps arms contacting surfaces 58 and 64, outwardly from theserrations 66 and 68. This occurs when the serrations 66 and 68 moverelative to each other from the mated position (apex to recess) to anunmated position (apex to apex). Clamp 46, 48, 50, and 52 maintainpressure between surfaces 60 and 62 of tongues 42 and 44, to again forcemating of the serrations 66 and 68 at any of the plurality of positions.First and second tongues 42A and 44A may also include serrations 66 and68, FIG. 9.

FIG. 6 shows serrations 72 and 74 which biases the movement of tongue 44into the extended position, toward the right. This feature would preventloosening of the adjustable member 20 once it is inserted within eye 16.

FIG. 7 describes an additional element to the prior embodiments whichexternalizes in ears 76 and 78, formed or otherwise rigidly fixed totongues 42 and 44. Surgical implements 80 and 82, visualized aselongated members having hooked end portions, engage ears 76 and 78 toseparate or close tongues 42 and 44. Surgical implements may be employedduring the initial insertion of intraocular lens 10 or post operativelywhere fluids change the shape of eye 16. In the latter case, a largeincision of the eye is not necessary, since the implements may be pushedthrough the eye and removed after use without great disruption of thehealing process.

The intraocular lens of the present invention may further comprise means84 for continually forcing second tongue 44 away from first tongue 42connected to lens portion 12. FIG. 8 illustrates an embodiment offorcing means 84, which includes a pair of studs 86 and 88 engaging astretched elastomeric band 90. The force of band 90 may be predeterminedto prevent the wedging action of first and second members 18 and 20 fromdamaging the angle 26 or any other portion of eye 16.

In operation, the surgeon selects an intraocular lens having the desiredoptical characteristics and inserts the same, through an incision, overthe iris. Tongues 42 and 44 are adjusted such that the outer edge oftongue 44 wedges into angle 26 and the end portions of first member 18wedge into angle 26. Where serrations are included, the surgeon selectsthe proper stop or position between the tongues. The eye is closed andexamined during the post-operative period to insure the wedging ofintraocular lens 10 does not dislocate. If the lens appears to be tooloose or too tight, surgical implements are used to adjust the positionof the tongues 42 and 44 without significant loss of aqueous humor; abrief and minor surgical procedure.

While in the foregoing specification embodiments of the invention havebeen set forth in considerable detail for purposes of making a completedisclosure of the invention, it will be apparent to those skilled in theart that numerous changes may be made in such details without departingfrom the spirit and principles of the invention.

What is claimed is:
 1. An intraocular lens for an eye comprising:a. lensportion adapted for positioning over the pupil; b. first member adaptedfor extending away from said lens portion to the periphery of the irisand being fixed to said lens portion; c. second adjustable memberadapted for extending a selected distance away from said lens portion tothe periphery of the iris and spaced along the periphery of the irisfrom said first member, said second adjustable member including a firstprojection connected to said lens portion; a second projection beingadjacent said first projection; and means for positioning said firstprojection in relation to said second projection.
 2. The intraocularlens of claim 1 in which said first member includes two spaced edgeportions, each adapted for extending away from said lens portion to theperiphery of the iris.
 3. The intraocular lens of claim 2 in which saidsecond adjustable member includes two spaced edge portions, each adaptedfor selectively extending away from said lens portion to the peripheryof the iris.
 4. The intraocular lens of claim 1 in which saidpositioning means includes clamping means for releasably holding saidfirst projection against said second projection.
 5. The intraocular lensof claim 4 in which said positioning means includes serrations on saidfirst and second projections, said serrations mating with each other ata plurality of positions between said adjacent first and secondprojections, said clamping means releasably mating said first and secondprojections.
 6. The intraocular lens of claim 5 in which said first andsecond projections each include an ear able to receive a force forpositioning said first and said projections in any of said plurality ofpositions where said serrations mate.
 7. The intraocular lens of claim 6in which said adjustable member additionally comprises means forcontinually forcing said second projection away from said firstprojection.
 8. The intraocular lens of claim 7 in which said firstmember includes two spaced edge portions, each adapted for extendingaway from said lens portion to the periphery of the iris.
 9. Theintraocular lens of claim 8 in which said second adjustable memberincludes two spaced edge portions, each adapted for selectivelyextending away from said lens portion to the periphery of the iris.